This invention relates to energy reclaiming and, in particular, to developing a high temperature lift in a vapor compression refrigeration system to enhance the system's heat reclaiming characteristics.
Most efforts heretofore directed toward recovering energy normally rejected from refrigeration systems have been relatively unsuccessful. The reason for this lack of success is basically due to the fact that the energy rejected from these systems is at or close to the refrigerant saturation condition. In many vapor compression cycles, the saturation temperature of the refrigerant seldom exceeds 120.degree. F. even when a highly efficient compressor is employed. Consequently, this low temperature energy cannot be readily utilized in most domestic and industrial applications which, for the most part, demand higher temperatures.
The present invention involves a high lift circuit suitable for use in conjunction with a conventional vapor compression refrigeration cycle that is capable of developing high temperatures on the high pressure side of the system to enhance the heat reclaiming characteristics of the system. This high lift is achieved by exposing refrigerant vapors discharged from the compressor to a strong absorbent solution. The discharge refrigerant vapors are partially absorbed and condensed by the solution, thus creating a mixture that is at a temperature level well above that normally attainable in the art. The high temperature energy is recovered in a heat exchanger. Energy remaining in the unabsorbed vapors is utilized to reconcentrate the diluted solution. Pure refrigerant is separated from the solution and reused in the refrigeration system, while the reconcentrated solution is recycled through the high lift circuit.
In U.S. Pat. No. 2,307,380 to Baker, a refrigeration system is disclosed which brings together some of the principles utilized in both the absorption and vapor compression refrigeration art. The Baker system involves a basic ammonia-water absorption cycle. A mechanical compressor is employed to provide energy for concentrating the absorbent solution rather than a more conventional heat actuated generator. The energy rejected from the Baker system is at or about the saturation temperature of the refrigerant and, as a consequence, cannot readily be reclaimed. As such, the system suffers from the same disadvantages found in the prior art.